On one occasion Dattatreya watched a deer. Nimble and swift of foot, it was on guard and alert. A hunter who failed to catch it and then realized that the animal was interested in or distracted by music. Knowing its vulnerability, he distracted it and caught it.

Any vulnerability is a weakness on the spiritual path. One loses alertness. Ekagrata or one-pointedness is lost. In no time, the sadhak who has raised himself with great effort is plunged into rajas and tamas. One should always be aware of one's vulnerable point and be alert on the path so that one does not go astray.

Another Interpretation

The deer, with its keen sense of hearing. It listens intently and is wary of all noises, but is lured to its doom by the melody of the deer hunter's flute.

Like the deer, we keep our ears alert for every bit of news, rumor, and gossip, and are skeptical about much that we hear. But we become spellbound by certain words, which, due to our desires, attachments, cravings, and vasanas (subtle impressions from the past), we delight to hear. This tendency creates misery for others and ourselves. (Source: The Himalayan Masters: A Living Tradition by Pandit Rajmani Tigunait, PhD)